MOUNT FOR CONTROLLING OR ISOLATING VIBRATION

An isolating mount for connecting two parts or mechanisms includes a rigid bushing surrounded by a resilient block which includes closed cavities on opposite sides of said bushing located along a first plane parallel to the longitudinal axis of said bushing and a passage formed by pipes extending outside the mount between the cavities. A quantity of liquid fills the cavities and passage, providing a liquid column of predetermined inertia in the passage between the cavities for controlling the frequency and amplitude of forces transmitted through the bushing to provide tuning of the damping characteristics of the mount to preselected frequencies of vibration. A rigid outer body surrounds and contacts the block and exerts compressive force thereon substantially along the first plane. The bushing is connected to one of the two parts to be isolated and the outer body is connected to the other of the two parts. A fitting in the passage permits modification of the condition of the liquid, as by injection of liquid under predetermined pressure in the closed liquid damping circuit of the mount. Also disclosed are systems in which the effective length or diameter of the passage can be changed. Arrangements for interactively controlling such liquid injection, for example in response to engine or vehicle operating conditions, are also disclosed, along with (optionally) adjusting the opening of a metering valve connected to control flow in the passage.